Testicular cancer is an abnormal, uncontrolled growth of cells that form a tumor in one or both testicles. Males typically have two testicles (testes, gonads) that are located in the scrotum, a pouch of loose skin found below and at the base of the penis. The testicles make sperm and male hormones (mainly testosterone) that regulate the development of sex (reproductive) organs and the adult male maturation process.

Testicular cancer is mostly a disease of young and middle-aged men. About half of testicular cancers occur in men between 20 and 34 years of age, and the average age at diagnosis is 33. According to the American Cancer Society, about 9,300 men are diagnosed with testicular cancer in the United States each year and about 400 men die of it.

Testicular cancer is one of the most treatable forms of cancer, with a 5-year relative survival rate of 99% for localized cancer (that which has not spread beyond the testicle). However, most types can spread if left untreated, invading and damaging the other testicle and spreading to the lymph nodes or vital organs, such as the lungs. The 5-year survival rate for regional cancer — meaning it has spread to nearby lymph nodes or tissues — is 96%, while the rate for distant cancer — meaning is has spread to organs or lymph nodes away from the tumor — is 73%. Early detection and treatment is crucial to a good outcome.

Germ cell tumors —This type affects cells within the testicles that make sperm. Germ cell tumors account for more than 90% of testicular cancers. These cancers are separated into two groups, seminomas and non-seminomatous germ cell tumors (nonseminomas), which occur with about equal frequency. Some germ cell tumors contain both seminoma and non-seminomatous germ cell tumor tissue.

Seminomas are less aggressive, which means they tend to grow slowly and are less likely to spread (metastasize) to other parts of the body. There are two types of seminomas: classical (or typical), which make up about 95% of seminomas, and spermatocytic, which are rare and tend to occur in older men.

Non-seminomatous germ cell tumor (nonseminomas) include four tumor types: yolk sac tumors, teratomas, embryonal carcinomas, and choriocarcinomas. They often occur earlier in life and grow and spread more quickly than seminomas.

Stromal tumors — Fewer than 5% of testicular tumors in adults but as many as 20% of testicular tumors in children are stromal tumors. These tumors form in the tissues that support the testicles and make hormones. These types of tumors are usually noncancerous (benign). The two main types of stromal tumors are:

Leydig cell tumors — These form in the cells that make male sex hormones, such as testosterone. The tumors themselves may make male sex hormones and sometimes they make the female sex hormone estrogen, which can lead to breast enlargement.

Sertoli cell tumors — These affect the cells that support germ cells, which make sperm.

Sometimes other types of cancer, such as lymphoma, spread from other parts of the body to the testicles, but these are not true testicular cancers and they are treated differently than testicular cancer.

Testicular cancer is usually first detected as a painless lump or swelling in the testicle. Most often, affected males find these tumors themselves—either by chance or while examining their testicles—but tumors may also be discovered during a routine physical exam or a medical workup that is being done for other purposes, such as an evaluation of infertility.

Testicular cancer may give no warning signs or it may cause subtle symptoms, such as:

Heaviness or a collection of fluid in the scrotum

A dull ache in the abdomen or groin

Pain in the testicle

Breast growth or soreness

Early (precocious) puberty in boys with signs such as deepening of the voice and/or growth of facial and body hair

These symptoms can be caused by conditions other than cancer, such as injury or inflammation, but they should always be evaluated by a healthcare practitioner.

There are no tests available to screen for testicular cancer. To date, no studies have been done to find out whether testicular self-exams, regular exams by a healthcare practitioner, or other screening tests in men with no symptoms would decrease the risk of testicular cancer deaths.

Some healthcare practitioners recommend that males between the ages of 15 and 55 perform a monthly self-examination to identify any changes in their testicles.

Most health practitioners agree that a testicular exam should be part of every general physical exam.

The American Cancer Society recommends a testicular exam as part of a routine cancer-related checkup, but it does not have a recommendation regarding testicular self-exams for all males.

Males who are at increased risk for testicular cancer may wish to consider performing monthly self-exams.

Determine whether the cancer has spread and, if so, what other organs and tissues are affected

Monitor the effectiveness of treatment and monitor for the return (recurrence) of cancer

Clinical Evaluation

The process of diagnosing testicular cancer begins with a medical history and physical exam. During the physical exam, a healthcare practitioner will:

Examine the patient's testicles for signs of swelling, tenderness or hardening

Press on the lymph nodes that lie beneath the skin in the groin, abdomen, upper chest, and neck to check for swelling or hardness

Examine the patient's abdomen for signs of liver enlargement

Examine the patient's breasts and nipples for signs of enlargement and tenderness

To obtain a medical history, a healthcare practitioner will ask about any recent changes in the person's health or new symptoms that he may have noticed. The patient will also be asked about his past health history, particularly whether he has any of the conditions that put him at increased risk for testicular cancer. Finally, he will be asked about the health of close family members, especially those who have had testicular cancer.

Non-Laboratory Tests

An ultrasound exam of the scrotum and testicles is often the first diagnostic test performed when testicular cancer is suspected. Ultrasound uses sound waves to create images of organs and tissues. Those images, called sonograms, can be viewed on a monitor while the exam is being performed. Ultrasound can detect the presence, size, and consistency of a testicular tumor, and it can be used to help differentiate cancer from other conditions, such as infection or structural abnormalities within the testicle.

Blood tests to check for elevated amounts of the following proteins, or tumor markers, that are made by some testicular cancers may be performed.

AFP (alpha-fetoprotein)—Nonseminoma germ cell tumors often make AFP. Seminoma germ cell tumors do not. Therefore, if someone's AFP level is elevated, his health care team will know that his tumor is composed, at least in part, of nonseminoma cells and the cancer should be treated as a nonseminoma.

Stromal tumors (Leydig cell tumors and Sertoli cell tumors) do not make AFP or hCG, so they will not cause blood levels of these tumor markers to rise.

Lactate dehydrogenase (LD or LDH) levels can rise in the presence of most types of testicular cancer. LD is an enzyme found in many body tissues that is released into the bloodstream when cellular damage occurs. It is not specific for testicular cancer; many other health conditions can cause LD levels to rise. When testicular cancer is present, high LD levels may indicate that the cancer is widespread.

When a solid mass is detected in a testicle during an ultrasound exam, healthcare practitioners often recommend surgery to remove the entire testicle, but usually only the affected testicle (see Other Diagnostic Procedures below). After surgery, the affected person's tumor marker levels will be measured again to help his health care team determine the extent (stage) of his cancer. Elevated tumor marker levels after surgery may be an indication that the cancer has spread to other parts of the body.

Tumor marker tests are likely to be a part of a testicular cancer patient's ongoing cancer care. They can be helpful in monitoring the person's response to treatment as well as detecting the recurrence of testicular cancer.

Other Diagnostic Procedures

Histologic examination:
The standard procedure for confirming a suspected diagnosis of testicular cancer is to remove the entire affected testicle. A pathologist will look at pieces of the mass and testicular tissue under a microscope. If cancer cells are found, the pathologist will report what types of cancer cells are present. A biopsy—removing a small sample of the testicular tumor for testing—is usually not done because this might cause the spread of cancer cells to other parts of the body (metastasis).

The procedure used to remove a testicle is called radical inguinal orchiectomy. In addition to providing a diagnostic specimen, it is the preferred treatment for most testicular cancers. The procedure involves making an opening in the groin through which the testicle and spermatic cord are released from the scrotum and removed. The procedure is done through the groin and not the scrotum to avoid spreading cancer cells to other parts of the body (metastasis). Likewise, the spermatic cord is removed because it contains the vas deferens, blood, and lymph vessels, all of which could carry cancer cells out of the testicle to other parts of the body.

Imaging tests:
Once a diagnosis of testicular cancer has been made, additional procedures may be recommended to find out whether the cancer has spread.

A chest X-ray may be done to look for masses in the lungs.

CT scans of the abdomen, pelvis, and possibly the chest may be done to determine whether the cancer has spread to lymph nodes, organs, or tissues in any of those areas.

MRI scan of the brain and spinal cord is typically done only if the healthcare practitioner has reason to believe that the cancer might have spread to this area.

A PET scan, which can help spot smaller collections of cancer cells, such as in the lymph nodes, might be done, but it is more useful for seminomas than for non-seminomas.

A bone scan could be done if there is bone pain, which suggests the cancer may possibly have spread to the bones.

These procedures are likely to be a part of someone's ongoing cancer care. They can be helpful in monitoring the body's response to treatment as well as detecting recurrence of testicular cancer.

Often, a combination of surgery, radiation therapy, and/or chemotherapy is used to treat testicular cancer.

As discussed in the Tests section of this article, surgical removal of the entire affected testicle is often done to establish a diagnosis of testicular cancer. (Usually, only the one affected testicle is removed, not both.) This treats the cancer as well. Surgery is typically done for all testicular cancers, even if the cancer has spread. Depending on the type and extent (stage) of the cancer, lymph nodes may be surgically removed from the abdomen at the same time that the testicle is removed or during a second procedure.

Radiation therapy is a common follow-up to surgery, especially for seminomas. These tumors are likely to be destroyed by radiation, while non-seminomatous germ cell tumors are not. The goal of radiation therapy is to destroy any cancer that may be growing in lymph nodes in the abdomen.

Chemotherapy may be used after surgery to destroy cancer cells that could have been left behind. Chemotherapy is an important treatment for cancer that has spread beyond the testicle or has a high risk for recurrence.

Research is ongoing to improve testicular cancer treatments. For example, certain changes in DNA (mutations) have been found in testicular cancers that do not respond well to chemotherapy. These findings may help to identify patients who will not benefit from chemotherapy. Further, this information could lead to the development of new drugs to treat testicular cancer by targeting specific mutations.

Additionally, researchers have determined that inherited variations in certain genes could increase the risk of testicular cancer, which might be able to help identify men at higher risk for the disease. However, additional studies need to be done.

Every person who is diagnosed with cancer faces difficult decisions. A diagnosis of testicular cancer comes with added concerns about how treatment could affect a man's physical appearance, sex drive, sexual performance, and ability to father children. For more information about testicular cancer treatments, including clinical trials, visit the National Cancer Institute's website, the American Cancer Society's website, or Cancer.Net.

(February 12, 2016) What are the Risk Factors for Testicular Cancer? American Cancer Society. Available online at https://www.cancer.org/cancer/testicular-cancer/causes-risks-prevention/risk-factors.html. Accessed on 2/13/18.

2006 July 26, Revised). Detailed Guide: Testicular Cancer, What Are the Key Statistics About Testicular Cancer? American Cancer Society [On-line information]. Available online through http://www.cancer.org.